1. Field of the Invention
This invention relates to instrumentation to aid a docking pilot in his endeavor to dock a large ship, and more specifically, to an electronic system employing a multiplicity of electronic subsystems operating in concert to quickly and efficiently provide information which the docking pilot requires during the approach, static alignment and terminal maneuver phases of the docking process. 2. Description of the Prior Art
The large masses, energies and momenta of large ships, the time lag in the perception of dynamic changes and the precision to which a large ship must be controlled, dictate the need for instruments to provide precision information to aid the docking pilot in the decision making process prior to the issuance of operational commands. Prior art devices and systems are limited in their capability and do not provide sufficient timely data to efficiently aid the docking pilot in his endeavors. Most systems, such as the docking sonar, are ship based and while the docking sonar offers the advantage of precision speed measurement without cooperative equipment ashore, the information from this subsystem does not include such data as orientation and distance to the jetty, which in the prior art are supplied by the human eye or ship's velocity normal to the jetty which may be supplied by a jetty based, side-looking sonar. Orientation and distance supplied by the human eye cannot be considered as precision data, and sonar signals from the ship based and jetty based sonar systems which provide velocity information may be lost because of air bubbles or mud swept into the sonar transmission path by the propellers of the ship or the tugs which provide the docking power. Replacement of the sonars with doppler radar systems will provide continuous velocity information but will still not supply the full complement of needed data. Various other devices, such as lasers, transponders, turn-rate gyros, precision hyperbolic navigators, and tellurometers have been considered for use in various systems, all of which have failed to supply the operational data required for efficient, safe, docking operations.
What is required to effectuate reliable and efficient docking of large ships is a combination of appropriate sensors which act in concert to provide raw docking data to a computer wherein this data is processed to provide meaningful display formats which are utilized in the decision making process or to provide automatic control signals for the tugs and other propulsion devices.